Research of static and dynamic characteristics of a voltage converter with soft switching running on arc load

Abstract

Purpose. The purpose of the work is to ensure the improvement of the regulation quality of pulsed energy converters with simultaneous exclusion of undesirable dynamic modes from its dynamics. Construction of a simulation model of a bridge converter with phase control and soft switching operating on an arc load, studying static and dynamic characteristics, analyzing static and dynamic modes of a closed current stabilization system, studying the nonlinear dynamic properties of the considered converter with PWM, comparative analysis of the frequency characteristics of a real closed pulse system with the characteristics of its linear model.Methodology. Fundamental principles of feedback theory, frequency analysis of electrical circuit stability and control, mathematical modeling and spectral analysis of processes in nonlinear discrete systems, digital signal processing and experimental determination of characteristics and parameters of automatic control systems. The use of engineering techniques and universal computer programs based on new solutions of the matrix equations of circuits, which allow to perform time-consuming calculations of frequency characteristics that take into account the nonlinear nature of processes in closed modern high-power pulse systems at a qualitatively different level.Findings. The proposed current control system based on a converter with soft switching transistors has sufficient reliability and service life, allows to obtain high efficiency as well as quality and accuracy indicators in conditions of uncertainty of object parameters and disturbances. A technique has been developed for designing the Bode-optimal frequency characteristics of the loop gain of the considered converter with PWM, in the possibility of controlling the static and choosing the dynamic instability of the output current, in ensuring stable operation and eliminating the self-oscillating mode of the stabilized converter operating on an arbitrary complex load.Originality. The theory of frequency control has been further developed by extending it to a new class of objects — power sources for electrical technologies with improved quality and accuracy indicators, which makes it possible to raise welding technologies and related technologies to a higher level, to solve many problems, including the problem of improving the final product quality.Practical value. The analysis of static and dynamic characteristics considered in the article and the use of new methods for calculating and measuring the equivalent frequency characteristics of converting devices with PWM should be considered as one of the stages of creating engineering methods for synthesizing power supply regulators, considering the latter as essentially nonlinear systems and taking into account the possibility of undesirable dynamic modes . The closed-loop method allows to determine the frequency characteristics of the loop gain function of a PWM converter that adequately reflects the stability conditions and possible lasing modes.